Centrifugal casting machine



2. Shets-Sheet 1 Filed Aug. 22, 1933 Aug. 7, 1934. w A QUBRIDGE 1,969,623

CENTRIFUGAL CASTING MACHINE Filed Aug. 22, 1933 2 Sheets-Sheet 2 Patented Aug. 7, 1934 UNITED STATES PATENT OFFICE Application August 22, 1933, Serial No. 686,285 In Great Britain June 29, 1933 6 Claims.

This invention relates to centrifugal casting machines of the kind in which the mould is made in separable parts which are relatively movable along the axis of rotation and are adapted to be brought together during the casting process and to be subsequently separated to permit of the withdrawal of the casting.

In the lighter class of machines of this type one part of the mould rotates the other preferably by frictional contact, but in the heavier machines, which are employed for producing castings of relatively large diameters, it has been usual to secure the two parts of the mould together in a positive manner by means of bolts and this has involved the provision at the front end of the cylindrical part of the mould, where the molten metal is introduced, of a deep and heavy outwardly directed flange.

It is found that after a number of successive castings have been made with these machines, there is a tendency for the cylindrical mould part to develop cracks at the flanged front end, and eventually to fly, owing to the severe internal stresses which are set up by the differences in temperature between the body of the said mould part, which is of uniform thickness, and the increased mass of metal at the flanged end, the former acquiring a veryhigh temperature whilst the latter remains comparatively cool.

The primary object of the present invention is to remedy this dangerous defect by means of an arrangement which, without affecting the normal operation of the machine, permits of the use of a cylindrical mould having a uniform wall section. A further object of the invention is to enable the front plate to be readily removed and exchanged.

A centrifugal casting machine of the kind herein referred to constructed in accordance with this invention is characterized by an arrangement in which the means employed for mounting and rotating the front plate are entirely independent of the cylindrical part of the mould. The improved machine is further characterized in that the front plate, instead of being carried directly by the slide or saddle by which it is moved towards and away from the cylindrical mould is detachably mounted in a rotatable annular plate thereon.

In the accompanying drawings,

Figure 1 is a side view partly in section of a centrifugal casting machine of the kind herein referred to embodying the present improvements.

Figure 2 is a front or end view of the same as seen from the left-hand of Figure 1, with the pouring spout removed.

Figure 3 is an enlarged detail view illustrating the manner in which the front plate is detachably mounted.

Throughout the drawings like parts are designated by similar reference characters.

Referring to the construction shown in the drawings, a represents the bed of the machine, b a headstock fixed thereto, a a driving shaft rotatably mounted in said headstock, and d a face plate fixed to the end of the driving shaft. e is a slide or saddle movable along the bed of the machine towards and away from the face plate, 1. f are a pair of gripping jaws pivotally mounted on saidslide and g is an annular plate rotatably supported by and between said jaws.

The cylindrical mould h is adapted to be clamped, as usual, to the face plate d for which purpose it may be formed at its rear ,end with a shallow flange h otherwise the wall of the mould is of uniform section except for a shallow recess h at its other end.

The front plate 2 is detachably secured by bolts or screws 7 to the annular plate g and is formed on its rear face with a shallow spigot i adapted to engage the recess 71. in the front end of the cylindrical mould which, whilst being supported thereby, is free to expand in a radial direction without stressing the front plate.

It will here be observed that there is no driving connection whatever between the cylindrical mould h and the front plate i. The rotation of the latter at the same speed as the former is effected by means of driving bolts is carried by and projecting from the face plate 41 and adapted for detachable connection by means of taper cottars l with the annular plate 9 to which, as aforesaid, the front plate is bolted. The said driving bolts are adjusted in the face plate according to the length of the cylindrical mould by means of nuts k and when the slide e is moved to bring the front plate up to the cylindrical mould the flange i thereon is caused to seat closely in the recess h in the end of the latter as the taper cottars are driven home in the ends of the bolts.

Longitudinal expansion of the cylindrical mould h is provided for by fitting the ends of the bolts k, where they pass freely through plain holes in the face plate, with springs m arranged put on the springs by adjusting. the nuts k at the front of the face plate.

In setting up the machine for the casting operation the slide e is moved toward the left-' hand end of the machine to enable the cylindrical mould h to be clamped in position against the face plate d. The front plate i is then bolted in position to the annular plate a. The slide is next moved along the bed to bring the front plate up to the cylindrical mould, the endsof the bolts is passing through holes in the annular plate, after which the taper cottars l are driven home.

up by moving a driving belt from a loose to a fixed pulley on the driving shaft 0. The pouring spout n is them moved into its operative position as shown and the molten metal poured into the rapidly rotating mould.

At the conclusion of the casting process the operations above detailed are reversed, that is to say, the pouring spout n is withdrawn, the nuts k screwed back and the bolts is released by knocking out the cottars Z. The slide e is then moved away to the left carrying the front plate with it and the casting finally ejected from the cylindrical mould by means of the plunger 0 which is carried by a spindle 12 passing through the tubular driving shaft 0. said spindle has a screw-threaded portion working in a fixed nut q and is provided with a hand wheel 1' for rotating it.

The advantages of the above described metho of mounting and rotating the front plate in permitting of the use of cylindrical moulds of uniform wall section will be appreciated when it is remembered that the cylindrical mould during successive casting operations acquires a very high temperature, approaching red heat, especially at the front end where the molten metal is poured in. It is therefore essential for the safe and economical working of the machine to avoid any appreciable variation in the wall section of the mould.

l. A centrifugal metal-casting machine comprising a face plate mounted for rotation, and a front plate, said plates having their adjacent opposed faces respectively formed with axially extending centering means and adapted to receive and frictionally hold between them a cylindrical mold part, said respective centering means being adapted to be received in, and engage the inner faces of, the respective end portions of such mold part, whereby the latter will be centered and left free to expand radially as the casting operation progresses, in combination with a plurality of bolts radially outside of said mold part and respectively passing through the respective plates to drive the front plate from the face plate, said bolts constituting the sole positive driving connecting means, between said plates and serving to'detachably hold said plates in operative casting relationship, and yielding means associated with said bolts for holding said plates in frictional engagement with the cylindrical mold part while permitting the front plate to move axially away from said face plate to compensate for the axial expansion of the cylindrical mold part.

2. A centrifugal metal-casting machine comprising a face plate mounted for rotation, a front plate, means for connecting said front plate to said face plate to rotate the former from the The machine is then started The rear end of ,point adjacent its rear end engaging the face plate and from said point to its extreme front edge face at no point exceeding said uniform thickness. I

3. A centrifugal metal-casting machine comprising a face plate mounted for rotation, a front plate, and means for connecting said front plate to the face plate to rotate the former from the latter, in combination with a cylindrical mold part fitting between said plates and having oppositely presented annular end flanges forming interior annular end recesses at the respective end portions of said mold part, said plates being formed on their adjacent opposed faces with annular centering flanges fitting in said recesses respectively and engaging the opposed faces of the respective end flanges of'said mold part.

4. A centrifugal metal-casting machine comprising a face plate mounted for rotation, a front plate, means for connecting said front plate to said face plate to rotate the former from the latter, and yielding means associated with said connecting means whereby said front plate may move axially with relation to said face plate during a casting operation, in combination with a cylindrical mold part fitting between said plates, said plates being formed on I their adjacent opposed faces with axially extending centering means respectively received in, and engaging the inner faces of, the respective end portions of said cylindrical mold part.

5. A centrifugal metal-casting machine com prising a faceplate mounted for rotation, and a front plate, said plates having their adjacent opposed faces respectively provided with axially extending centering means and being adapted to receive between them, and frictionally hold, a cylindrical mold part, said respective centering means being adapted to be received in, and engage the inner faces of, the respective end portions of said mold part, in combination with means for connecting said front plate to said face plate to rotate the former from the latter and to frictionally grip and hold the cylindrical mold part between said plates, and yielding means associated with said connecting means whereby said front plate may move axially with relation to said face plate during a casting operation.

6. A centrifugal metal-casting machine comprising a face plate mounted for rotation, and a front plate, said plates having their adjacent opposed faces respectively provided with axially extending centering means and being adapted to receive and frictionally hold between them a cylindrical mold part, and said centering means being adapted to be received inside of the respective end portions of the cylindrical mold part, in combination with means for connecting said front plate to said face plate to drive the former from the latter and to hold the respective plates in frictional gripping contact with the corresponding ends of the mold part.

WILLIAM ARTHUR OUBRIDGE. 

